Of course there will be similar things as an original/previous series, but SEED Destiny pretty much blatantly copies stuff with the ZAKU Warrior, GOUF Ignited, DOM Trooper, and such right down to general names, appearances, functions, weapons, etc. To a lesser extent, the Akatsuki with the Hyaku Shiki + Strike/Providence, the Murasame with the Zeta, the Destroy Gundam with the Big Zam + Psyco Gundam, and so on. And then ending it by pretty much copy/pasting the Freedom, Justice, and Providence, but with slightly different coloring and tweaks here and there and it just gives off a vibe of laziness that I just can't shake.

Not like how SEED with the GINN, CGUE, GuAIZ, and other MS were obviously influenced by the Zaku II and other UC-era MS, but at least they kept their own original identity that set them apart. That's what made their designs more appealing to me.

Well SEED had much more time in development while Destiny was rushed out the door because of SEED hype and demand. So what did you expect them to do in such a short time? They didn't even have the ability to get the mid to final parts of Destiny's story done right when the clock was ticking.